This invention pertains to a new and distinct cultivar of Persian walnut (Juglans regia) tree adapted to northern growing climates of the U.S.A. designated on the USDA Plant Hardiness Zone Map as Zone 5a and Zone 4b. The nuts are a smaller size than eating nuts commercially-produced in California and Oregon. The tree is small in stature and is adapted to colder climates. The present walnut tree is most suited as an ornamental or a non-commercial walnut producer, unless medium to small walnuts become desirable by consumers in the future.
The tree originated from a collection of open pollinated nuts collected and germinated by hobbyist nut growers from unpatented Persian walnut trees growing in central and eastern Iowa, U.S.A. for which the identity of the female parent was not recorded. The collection of trees were planted at the Iowa State University Horticulture Farm, Ames, Iowa, U.S.A. in 1971 by Mr. Allen R. Beck. Each of the trees were designated by row letter and tree number in the row, and were evaluated for resistance to low winter temperatures along with several unpatented Persian walnut cultivars grafted on unpatented eastern black walnut (Juglans nigra). The tree presently claimed was designated and tested as ISU71-E18 in the selection process. The present inventor assumed responsibility for the project in 1975, and subsequently identified the claimed tree in 1986 as one which exhibited outstanding hardiness characteristics compared to other selections or the grafted cultivars.
Following recognition that ISU71-E18 had outstanding hardiness characteristics, it was asexually propagated by topworking onto an established unpatented eastern black walnut (Juglans nigra) tree in 1988, and budded on unpatented eastern black walnut rootstock in 1989 and lined out in the field in 1990. The resulting trees were true to the parent in all respects including general appearance, shape, branching, leaves, flowering, fruit, and resistance to low winter temperatures.
Past literature and growth characteristics of the claimed tree suggest that one of the parents was probably unpatented xe2x80x98Hansenxe2x80x99, and possibly unpatented xe2x80x98Colbyxe2x80x99 Persian walnuts. In 1972, Beck reported that the 73 trees planted in 1971 were supplied by Frank Kosek, Cedar Rapids, Iowa, USA (10); Frank Martzahn, Davenport, Iowa, USA (3); and Archie Sparks, Beaver, Iowa, USA (60). Mr. Sparks (personnel communication) revealed that the trees he supplied originated from nuts obtained from a collection of Persian walnut trees growing in Huxley, Iowa, U.S.A. that were established by Mr. Steward Burhow. In 1964, Burhow reported that xe2x80x98Hansenxe2x80x99 and xe2x80x98Colbyxe2x80x99 were his most productive trees, and that xe2x80x98Hansenxe2x80x99 had a tendency to produce nuts that xe2x80x9cturned black and remained unfilled.xe2x80x9d Other unpatented Persian walnut trees grown by Mr. Burhow were xe2x80x98Broadviewxe2x80x99, xe2x80x98R24T1xe2x80x99, and xe2x80x98Caeserxe2x80x99.
xe2x80x98Hansonxe2x80x99 was discovered in Clay Center, Ohio, USA by the father of Awalt Hansen. It was selected in 1934 and introduced in 1950. Seed that produced the tree is considered to be of German origin. Nuts are small to medium (58 nuts per pound), round; thin shelled; mild flavor, sweet, good; kernel percentage high (60%). Tree is small, essentially dwarf, and bears early. It is the most widely planted, winter hardy cultivar.
In comparison to xe2x80x98Hansenxe2x80x99, the claimed tree is similar in stature and hardier; produces larger nuts; similar in earliness of bearing; and has a tendency to produce xe2x80x9cblankxe2x80x9d nuts.
xe2x80x98Colbyxe2x80x99 originated in Urbana, Ill. by A.S. Colby, Illinois Agricultural Experiment Station, from an open pollinated seedling of unpatented xe2x80x98Crath 10xe2x80x99 (Carpathian type seed from Cosseev, Poland obtained in 1934), and was introduced in 1952. Nut is of medium size, thin shelled, well-sealed; 53% kernel that is plump, good flavor and matures early. Tree is not considered as hardy as other Persian walnut cultivars recommended for northern climates.
In comparison with xe2x80x98Colbyxe2x80x99, the claimed tree produces nuts of similar size, shape, and kernel percentage, but is more hardy to cold temperatures.
xe2x80x98Broadviewxe2x80x99 originated in Westbank, British Columbia, Canada, from seed brought from Odessa Russia by the family of J.U. Gellatly, and was introduced in 1930. Nuts are medium to large, oblong, soft shelled, well sealed, 47% kernal. Tree is hardy and productive.
In comparison with xe2x80x98Broadviewxe2x80x99, the claimed tree produces smaller nuts of a different shape. The nuts of the claimed tree are rounder and larger than the nuts of xe2x80x98Broadviewxe2x80x99.
xe2x80x98R24T1xe2x80x99, although not known to be cultivated at the present time, was an unreleased, open pollinated Carpathian walnut seedling that originated from seed collected in 1936 in eastern Europe and shipped out of the Ukraine by Reverand Paul C. Crath. The seeds were distributed by the Wisconsin Horticulture Society in 1939 to the Tennessee Valley Authority and grown in a plantation at Norris, Tenn. The nuts were said to be of good size.
Little is known of xe2x80x98R24T1xe2x80x99, but based on historical accounts, the nuts were larger than produced by the claimed tree.
xe2x80x98Caesarxe2x80x99 was introduced in 1938 and originated in Roanoke, Va. by Harvey F. Stike from Carpathian-type walnut seed. The seed was imported by Paul Crath from Poland. Nuts are very large, very thin shelled; kernel is of good quality, but sometimes does not fully develop.
In comparison to xe2x80x98Caesarxe2x80x99 the claimed tree produces smaller sized nuts with slightly thicker shells.
A new and distinct cultivar of Persian walnut (Juglans regia) tree, as herein described and illustrated and characterized by being a hardy tree of a small size, slow growing with somewhat upright branches producing a globular shaped tree that is almost as broad as it is high, having a moderate to dense foliage, pinnately compound leaves with 7 to 9 elliptical leaflets, that bears fruit early predominately on the terminal of spurs with a portion of the crop produced laterally on shoots. Catkin buds withstand exposure to minus 26 degrees Fahrenheit, and trees have withstood minus 32 degrees Fahrenheit with minimal shoot injury. Produces medium size, thin-shelled, well-sealed nuts with plump, flavorful, mildly bitter, light colored kernels.
xe2x80x98Stark(copyright) Northern Prize (Domoto)xe2x80x99 is advantageous over xe2x80x98Hansenxe2x80x99 in that it produces larger nuts, although some are blank as in xe2x80x98Hansenxe2x80x99.
xe2x80x98Stark(copyright) Northern Prize (Domoto)xe2x80x99 is advantageous over xe2x80x98Colbyxe2x80x99 in that it is more winter hardy.